Production of linear aromatic polyesters



j hydroxide.

cording to this method really high-molecular polyesters United States Patent 3,028,364 PRODUCTION OF LINEAR AROMATIC POLYESTERS Andr Jan Conix, Hove-Antwerp, and Urbain Leopold Laridon, Mortsel-Antwerp, Belgium, assignors to Gevaert Photo-Producten N.V., Mortsel, Belgium, 2! company of Belgium No Drawing. Filed Apr. 1, 1958, Ser. No. 725,498 Claims priority, application Great Britain Apr. 2, 1957 3 Claims. (Cl. 260-47) This invention relates to the production of polymeric materials and particularly of linear aromatic polyesters.

It is known to prepare aromatic polyesters by causing terephthalic acid and derivatives to react with glycols having 2 to 12 carbon atoms. The most valuable representative of the series of polyesters thus obtained is polyethylene terephthalate.

It has also been proposed to produce aromatic polyesters by substituting diphenols for glycols in reactions with dicarboxylic acids but it Was found diflicult or impossible to obtain polyesters having sufiiciently high molecular weights. Accordingly for the production of polyesters of this type recourse has been had to the reaction between the free diphenol and the dihalide, usually the dichloride of the dicarboxyl acid, the reaction being carried out in the presence of a base for instance sodium It is very diflicult, however, to obtain ac which can be formed in filaments and films; moreover the reaction is not smooth and the reaction mass tends to become pasty, the end product frequently being yellow to brown.

Products of high-molecular weight can be obtained, however, according to British patent specification No. 621,102, by condensing the dicarboxylic acid with the diacetate of the diphenol or by reacting the dicarboxylic acid with the diphenol in the presence of acetic anhydride.

In the copending US. patent application Serial No. 702,252, a process is described for the production of linear aromatic polyesters by polycondensation of diphenols with aromatic dicarboxylic acids accordingv to which high molecular linear aromatic polyesters are obtained which dissolve in low boiling solvents by selecting as the diphenols those of the general formula or chemically equivalent derivatives thereof, such as diacetates and other diesters, and as dicarboxylic acids those of the general formula HO O C C OOH Q or chemically equivalent derivatives thereof, such as esters or anhydrides, wherein each of the R and R represents an alkylor aryl-substituted methylene group or forms part of a cycloaliphatic ring, or one represents such a group or forms part of such a ring, and the other represents an oxygen atom or a methyleneor carbonyl group.

The polycondensation is carried out according to the above-mentioned copending application by heating the dicarboxylic acid and the diphenol, preferably in the form of the diacetate e.g. to a temperature of 305 C.

It is therefore an object of the present invention to provide new linear aromatic polyesters which dissolve quite well in low-boiling solvents and show high softening temperature. A further object of the present invention is to provide a suitable method for the production of such linear aromatic polyesters. Still further objects "ice of the present invention will appear from the following description and claims.

It has now been found that if diphenols and dicarboxylic acids are condensed in a two-phase mixture of liquids, the acid chloride of the dicarboxylic acid being dissolved in organic liquid which is a solvent for the reaction product formed, and the bis-phenol being dissolved in another liquid which is immiscible with the former, it is possible to carry out the condensation reaction at room temperature and to obtain high molecular weight products which dissolve in low-boiling solvents.

It has further been found that this condensation method can be applied for obtained polyesters of high molecular Weight, starting from a wide variety of bis-phenols and dicarboxylic acids.

According to the present invention, a process for the production of linear aromatic polyesters comprises reacting phenolate of a diphenol of the general formula with a diacid chloride of an aromatic dicarboxylic acid of the general formula in which formulae the hydroxyl groups and the carboxyl groups may be in the paraor meta-position and wherein each of the R and R represents a single bond or an alkyl-, arylor halogen substituted methylene group or a carbon atom which forms part of the cycloaliphatic ring, or one represents such a group or form parts of such a ring or such a carbon atom, and the other represents an oxygen atom or a carbonylor sulphonyl group, or a saturated hydrocarbon radical such as a methyleneor ethylene group, the said reaction being carried out by dissolving the aromatic dicarboxylic acid chloride in a solvent for the reaction product and adding thereto the diphenolate dissolved in a solvent which is immiscible with the solvent in which the acid chloride is dissolved while maintaining the temperature at substantially room temperature and precipitating the reaction product, e.g. by pouring the reaction mixture into boiling water. The following are examples of such radicals:

a. and

wherein n and n each represents a positive number from 1 to 7,

Especially high-molecular weights are obtained if the reaction is carried out in the presence of a suitable catalyst, such as a quaternary ammonium compound. Examples ofsuch catalysts are trimethylbenzyl ammonium chloride, triethyl benzyl ammonium hydroxide, and triethyl benzyl ammonium chloride.

It is an important advantage of the present invention that the reaction may be carried out at room temperature and at atmospheric pressure in a liquid reaction medium consisting of non-miscible solvents which separately keep in dissolution the sodium diphenolate and the acid chloride together with the polyester formed. We use Water as the solvent for the diphenolates and methylene chloride as common solvent for the acid chlorides and the polyester formed during the reaction. Other water immiscible organic solvents can be used in association with water, such as dichloroethane, tetrachloroethane, benzene and toluene.

The diphenolates can be formed by dissolving the diphenols in water in the presence of equivalent quantities of metal hydroxides such as sodiumor potassium hydroxides. The dichlorides can be obtained a.o. by re action of the respective dicarboxylic acids with thionyl chloride.

The following are examples of aromatic dicarboxylic acids the dihalide of which can be used for preparing the polyesters according to the present invention:

4,4-dicarboxy-diphenyl, 4,4'-dicarboxy-diphenyl ether, 4,4-dicarboxy-diphenyl sulphone, 4,4-dicarhoxy-diphenyl methane,

1,2- and 1,1-(4,4'-dicarboxy-diphenyl)ethane, 4,4'-dicarboxy-benzophenone, 4,4-dicarboxy-diphenyl dichloromethane, 2,2-(4,4'-dicarboxy-diphenyl)propane, 2,2-(3,3'-dicarboxy-diphenyl)propane, 2,2-(4,4'-dicarboxy-diphenyl) 1,1-dimethylpropane, 3,3-(4,4'-dicarboxy-diphenyl)heptane, 3,3-(3,3'-dicarboxy-diphenyl)heptane, 1,1-(4,4-dicarboxy-diphenyl)propane, 1,1-(3,3'-dicarboxyediphenyl)propane,

1,1 or 2,2-(4,4'-dicarboxy-diphenyl)butane, 1,1 or 2,2-(4,4'-dicarboxy-diphenyl)pentane.

The following are bis-phenols the metal phenolates of which can be used for preparing the polyesters according to the present invention:

1,1-(4,4'-dihydroxy-diphenyl)-cyclohexane, l-phenyl- 1 1- (4,4-dihydroxy-diphenyl) methane, l-phenyl- 1 1- 4,4-dihydroxy-diphenyl) ethane, 4,4'-dihydroxy-diphenyl-sulphone,

2,2- (4,4-dihydroxy-3 ,3 '-dimethyl-diphenyl propane, 1,1,1-trichloro-2,2-(4,4'-dihdroxy-diphenyl) ethane, 2,2- 4,4'-dihydroxy-diphenyl propane, 2,2-(4,4'-dihydroxy-diphenyl) 1,1- dimethylpropane, 3 ,3- (4,4'-dihydroxy-diphenyl heptane,

1, 1-(4,4'-dihydroxy-diphenyl) propane,

1,1 or 2,2-(4,4'-dihydroxy-diphenyl) butane,

1,1-, 2,2- or 3,3- 4,4'-dihydroxy-diphenyl pentane.

The invention includes polyesters obtained by reacting a mixture of two or more of the specified diphenolates With one or more of the specified aromatic dicarboxylic acid chlorides or mixtures of two or more of these acid chlorides with one or more of the said diphenolates.

In this way, polyesters are obtained containi the recurring structural units according to the general formula:

wherein R and R represent radicals as defined above.

The following examples illustrate the invention without limiting, however, the scope thereof. The softening points are obtained on films prepared from the polyesters. The elongation of strips of films subjected to a load of 0.17 kg/mm. is measured in function of the temperature. The temperature where a large rise in elongation is observed is taken as the softening temperature. It is to be emphasized that these temperatures have only a comparative value and are not to be confounded with melting temperatures. In fact they correspond more or less with glass transition temperature.

Example 1 A filtered solution of 3.15 g. of di-p-carboxy-phenyl- 2,2-propane di-acid chloride in 20 cm. of methylene chloride is brought into a vessel, fitted with a stirrer and a dropping funnel. To this solution is added 0.05 g. of triethylbenzyl ammonium chloride. Under stirring and during 30 minutes, a solution of 2.3 g. of di-p-iydroxyphenyl-2,2-propane and 0.8 g. of sodium hydroxide in 20 cm. of water is dropwise added. The reaction tempera ture is held by cooling to approximately 25 C. The solution is subsequently stirred for 75 minutes. After this period, the reaction mixture became extremely viscous. The viscous mixture is brought into boiling water whereupon the polymer precipitates. The polymer is isolated by filtration and dried. The intrinsic viscosity of the polymer determined in dichloroethane solution at 25 C. is 1.9. The polymer dissolved in methylene chloride can be cast to tough, transparent, colorless films which are characterized by a low water-absorption and a high softening point (225 C.). This film material is particularly useful as base for photographic materials.

Example 2 A solution consisting of cm. of methylene chloride, 29.5 g. of the di-acid chloride of di-(p-carboxy-phenyl) ether and 0.5 g. of triethylbenzyl ammonium chloride is brought into a vessel, fitted with a stirrer and a dropping funnel. To this solution is dropwise added under vigorous stirring and during 35 minutes a solution of 22.8 g. di-(p-hydroxyphenyl)-2,2-propane and 8 g. of sodium hydroxide in 200 cm. of Water. The reaction mixture is subse uently stirred for 3 hours at a temperature of approximately 25 C. The viscous solution is brought into boiling water, whereupon the polymer precipitates, and can be isolated by filtration. The polymer has an intrinsic viscosity of 0.76 measured in a dichloroethane solution at 25 C. The polymer can be cast from a solution in methylene chloride to tough, transparent films which are characterized by a low water-absorption and a high softening point (200 (1.). Similarly, the polymer can be moulded into transparent objects showing a highimpact strength and a particularly high-distortion temperature.

Example 3 A polyester is prepared by proceeding as in Example 2 but using 1 mol of the di-acid chloride of 2,2-(4,4'-dicarboxy-diphenyl)propane and -1 mol of the di-sodium salt of 4,4'-dioxy-diphenyl-phenyl methane of the formula A'polyester, soluble in low-boiling chlorinated hydrocarbons such as methylene chloride, is obtained. The softening point of the films cast from solution, is 218 C.

Example 4 A polymer is prepared by proceeding as in Example 3 5 but using as starting materials the di-acid chloride of 2,2-(4,4-dicarboxy-diphenyl)propane and 4,4'-dioxy-diphenyl-l,l-cyclohexane of the formula Example 7 CH3 O B 1113 I l -000Q000C OC0- l- 1113 Y J 5.127 g. (0.02 mol) of 2,2-(4,4'-dihydroxy-3,3'-dimethyl-diphenyl)propane and 150 mg. of triethylbenzylammonium chloride were dissolved in 40.4 cm. of NaOH N. At a temperature not exceeding 23 C. this solution was added over a period of minutes to a 20 vigorously stirred suspension of 5.583 g. of diphenyl- A polyester soluble in methylene chloride and showing 4 1 1 in 50 s f 1 1 1 a softening Point of about is obtamai ethane. Stirring was continued for an additional 4 hours,

H2O CH2 Example 5 subsequently the upper layer was decanted and replaced OH l 1 3 l o (I: 000 s02 oo l. CH3 v ..l

4.566 g. (0.02 mol) of 2,2-(4,4'-dihydroxydiphenyl)pro- 0 by 100 cm. of distilled Water. The mixture was again pane and 150 mg. of triethylbenzylammonium chloride stirred for minutes. Subsequently the aqueous layer were dissolved in 40.4 cm. of NaOH N and 20 cm.. was decanted and removed. Upon pouring the organic of 1,1,2-trichloroethane were added. At a temperature layer into an excess of ethanol, a fibrous white polymer not exceeding 19 C., a solution of 6.864 g. of sulphone precipitated which could be isolated by filtration. The 4,4'-dibenzoylchloride in 60 cm. of 1,1,2-trichloroethane polymer is s l in methylene Chloride, 1,2-dich10r0- was added over a period of 15 minutes to the vigorously ethane, 1,1,2-trichloroethane, tetrachloroethane and distirred mixture. Stirring was continued for an additional oxane; from t se Solvents the P y can be cast into 150 minutes. Subsequently the upper aqueous layer was colorless, transparent films Showing good flexibility and decanted and replaced by 50 cm. of distilled water; h Softenlhg P0111t The intrinsic the mixture was again Stirred f 30 minutes This 40 vlscosity of the polymer, determined in tetrachloroethane cedure was repeated once more. The polymer was presolut1on amounts to cipitated into an excess of ethanol and is found to be Example 8 5.128 g. (0.02 mol) of 3,3-(4,4'-dihydroxy-diphenyl)pentane and 100 mg. of triethylbenzylammonium chloride Were dissolved in 40.4 cm. of NaOH N. At a p f fih'hs Showing h h y h a high Softening temperature not exceeding 20 C., this solution was Polht The mtrlnslc Q W of the P added over a period of 15 minutes to a vigorously stirred determined in tetrachloroethane solut1on amounts to 0.64. mixture of 5583 g of diphenyl 4,4I dicmbonyl chloride Example 6 in cm. of 1,1,2-trichloroethane. Stirring was continued for an additional 2 hours. Subsequently 40 cm. and 200 mg. of triethylbenzylammonium chloride were of l,1,2-trichloroethane and 100 cm. of water were dissolved in 40.0 cm. of NaOH N and 20 cm. of added to the viscous mixture and stirring continued for l,l,2-trichloroethane were added. At a temperature not 30 minutes. Subsequently the upper aqueous layer was exceeding 20 C. a solution of 6.424 g. of 4,4'-(2,2-prodecanted and replaced y 100 6111-3 0f Wfltef- The pylene)dibenzoylchloride in 40 cm. of l,l,2-trichloroture was ag Stirred f r 1 h ur. Su sequently the ethane was added over a period of 20 minutes to the P y Was Precipitated into an eXCeSS of ethanol- The vigorously stirred mixture. Stirring was continued for fibrous white polymer is soluble in methylene chloride, an additional 4 hours, subsequently the upper layer was 1,2-dichloroethane, 1,1,2-trichloroethane and tetrachlorodecanted and replaced by 100 cm. of distilled Water. ethane; from these solvents the polymer can be cast into The mixture was again stirred for 30 minutes. Subsecolorless, transparent films showing good flexibility and quently the upper layer was decanted and removed. Upon a high softening point (260-290 C.). The intrinsic pouring the organic layer into an excess of ethanol, a viscosity of the polymer, determined in tetrachloroethane fibrous white polymer precipitated which could be sepasolution amounts to 2.25.

soluble in methylene chloride, 1.,2-dichloroethane, 50 1,1,2-trichloroethane and tetrachloroethane. From these solvents the polymer can be cast into colorless, trans- 5.006 g. (0.02 mol) of 4,4-dihydroxydiphenylsulphone Z Example 9 ture. Stirring was continued for an additional 3 hours. The upper aqueous layer was decanted, and the residue washed with 2 crn. Water by stirring during 15 minutes. The aqueous layer was decanted and the residue was poured into ethanol. A fibrous white polymer was obtained, with an intrinsic viscosity determined in tetrachloroethane of 0.92 and a softening point of 180 C. it is soluble in methylene chloride, 1,1,2-trichloroethane, l,2dich oroethane, tetrachloroethane, dioxane and tetrahydrofurane.

Example 12 the mixture was again stirred for 30 minutes. Subsequently the aqueous layer was decanted and the polymer precipitated into an excess of ethanol. The fibrous white polymer is soluble in methylene chloride, 1,2-dichle-roethane, 1,1,2-trichloroethane, tetrachloroethane and dioxane; from these solvents the polymer can be cast into colorless, transparent films showing good flexibility and a high softening point (280-309 C.). The intrinsic viscosity of the polymer, determined in tetrachloroethane solution amounts to 1.95.

Example 10 CCls 9.525 g. (0.03 mol) of 1,1,1-trichloro-2,2-(4,4-dihydroxy-diphenyl)ethane was mixed with 45.5 cm. of NaOH 1.5 N at a temperature not exceeding --l0 C. and a solution of 150 mg. of triethylbenzylammonium chloride in 50 111. of methylene chloride was added. At a temperature not exceeding 5 C. a solution of .85 g. of diphenylether 4,4-dicarbonylchloride and 150 mg. of triethylbenzylarnmonium chloride in 50 cm. of methylenechloride was added over a period of minutes to the vigorously stirred. mixture. Stirring was continued for an additional 5 hours at a temperature not exceeding 4.566 g. (0.02 mol) of 2,2-(4,4'-dihydroxy-diphenyl)propane and 150 mg. of triethylbenzylarnmoniurn chloride were dissolved in 40.4 cm. of NaOI-l N and cm. of 1,1,2-trichloroethane were added. At a ten perature not exceeding 5 C., a. solution of 7.242 g. of 4,4-benzophenone dichloride dicarbonyl chloride in 30 cm. of 1,1,2-trichloroethane was added over a. period of minutes while the mixture was vigorously stirred. Stirring was continued for an additional 3 hours at a temperature slowly rising to 20 C. Subsequently the upper aqueous laye was decanted and replaced by 10 0111. of distilled water. The mixture was again stirred for minutes. Subsequently the aqueous layer was decanted removed. Upon pouring the organic layer into an excess of ethanol, at fibrous white polymer precipitated which could be isolated by filtration. The polymer is soluble in methylene chloride, 1,2-dichloroethanc, 1,1,2-trichloroethane, tetrachloroethane and dioxane; from these solvents the polymer can be cast into colorless, transparent films showing good flexibility and a high softening point (HO-260 C.). The intrinsic viscosity of the polymer, determined in tetrachlorocthane solution amounts to 0.90.

Example 11 0 C. Subsequently the upper aqueous layer was decanted and replaced by 100 cm. of distilled water. The mixture was again stirred for 1 hour. Subsequently the aqueous layer was decanted and the organic layer was poured into boiling water; a fibrous White polymer could easily be separated. The polymer is soluble in methylene chloride, 1,2-dichloroethane, 1,1,2-tricldoroet one, tetra chioroethane, dioxane and tetrahydrofurane. From these solvents the polymer can be cast into colorless, transparent showing good fiex'bility and a high. softening point (180 C). The intrinsic viscosity of the polymer, determined in tetrachloroethane solution amounts to 1.3.

We claim:

1. A process for preparing highly polymeric linear polyesters, having an intrinsic viscosity of at least 0.4 when measured in a solution of a chlorinated hydrocarbon, which comprises condensing a diacid halide of an aromatic dicarboxylic acid, dissolved in an alkyl halide which is a solvent for the polyester formed, with an alkali metal salt of a bis-phenol dissolved in water, the aromatic dicarboxylic acid is a member of the group consisting of of 10 minutes to the stirred solution at room tem era HOCOAr'R-Ar--COOH and the bisphenol is a member of the group consisting of I-IO-ArAr-OH and HO-Ar-RA1-OH in which formulae each of the links Ar and Ar represents a bivalent aromatic radical selected from the group consisting of an unsubstituted para-phenylene radical, a metaphenylene radical, a methyl substituted paraphenylene radical and R and R each represents a bivalent radical selected from the group consisting of an ether radical, a carbonyl radical, a sulphonyl radical, a saturated lower hydrocarbon radical, and a carbon atom which forms part of a cycloaliphatic ring, at least one of the radicals R and R is a bivalent saturated lower hydrocarbon radical selected from the group consisting of a lower alkyl-substituted methylene group, an aryl substituted methylene group, a lower alkyland aryl substituted methylene group, a halo-methyl substituted methylene group, a halogen-substituted methylene group and a carbon atom which forms part of a cycloaliphatic ring, whereby the polyester is dissolved in the alkyl halide as it is formed, permitting the formation of highly polymeric linear polyesters.

2. A process according to claim 1, wherein the condensation is carried out in the presence of a catalyst selected from the group consisting of the quaternary ammonium compounds.

3. A process according to claim 1 wherein suflicien-t water is added to the reaction mixture to precipitate the polymer formed.

References Cited in the file of this patent UNITED STATES PATENTS 2,595,343 Drewitt May 6, 1952 2,600,376 Caldwell June 17, 1952 2,808,394 Speck Oct. 1, 1957 2,839,508 Williams June 17, 1958 OTHER REFERENCES Conix: Ind. Eng. Chem., 52, 147-150 (1959). 

1. A PROCESS FOR PREPARING HIGHLY POLYMERIC LINEAR POLYESTERS, HAVING AN INTRINSIC VISCOSITY OF AT LEAST 0.4 WHEN MEASURED IN A SOLUTION OF A CHLORINATED HYDROCARBON, WHICH COMPRISES CONDENSING A DIACID HALIDE OF AN ARONATIC DICARBOXYLIC ACID, DISSOLVED IN AN ALKYL HALIDE WHICH IS A SOLVENT FOR THE POLYESTER FORMED, WITH AN ALKALI METAL SALT OF A BIS-PHENOL DISSOLVED IN WATER, THE AROMATIC DICARBOXYLIC ACID IS A MEMBER OF THE GROUP CONSISTING OF 